1. Field of the Invention
The present invention relates to a method of cleaning a liquid nozzle-formed face of a print unit that performs printing on a surface of a recording medium, to a cleaning device for an ink jet printing apparatus having a plurality of cleaning members using this cleaning method, and to an ink jet printing apparatus having this cleaning device.
2. Description of the Prior Art
Conventional ink jet printing apparatus are provided with a cleaning device for cleaning the surface of a print head formed with a plurality of ink nozzles because contamination of the nozzle-formed face will lead to a failure of the print head to eject ink. The cleaning device includes a wiper blade as a cleaning member. The wiper blade is made, for example, of an elastic material and is moved relative to the nozzle-formed face of the print head to bring its wipe portion into a sliding contact with the nozzle-formed face to remove ink adhering to it.
During this process, a cleaning performance (wiping performance) of the wiper blade depends on an ink adhesion state of the nozzle-formed face of the print head and a contact width over which the wipe portion of the wiper blade contacts the nozzle-formed face.
The result of verification as to the effect which the contact width between the wipe portion of the wiper blade and the nozzle-formed face has on the wiping performance will be described in the following.
FIG. 20 shows a state in which the end of the wiper blade 1004 is brought into contact with one surface of a transparent body 1002, such as a glass plate, of a predetermined width over a predetermined contact width Lc and is slid in a direction of arrow at a predetermined speed, for example 150 mm/s. The wiper blade 1004 is made of an elastic material (with Asca C scale hardness of 75) and is 10 mm in overall length and 0.7 mm in thickness.
In performing the verification, the contact width over which the wipe portion of the wiper blade 1004 contacts the nozzle-formed face is classified largely into three levels as shown in FIG. 21.
A first level of the contact width (overlapping length) Lc represents a state in which a contact width L1 is relatively small at about 0.3-0.7 mm when viewed directly from above, with only a widthwise edge of the end of the wipe portion in contact, as shown in FIG. 21A. A second level represents a state in which a contact width L2 is slightly larger at about 0.8-1.2 mm, with the widthwise edge as well as a widthwise area of the front surface of the wipe portion near its end in contact, as shown in FIG. 21B. A third level represents a state in which a thicker widthwise area of the front surface of the wipe portion near its end than in the second level contacts the transparent body over a relatively large contact width L3 of about 1.3-1.7 mm as shown in FIG. 21C.
The verification is performed by contacting the end of the wipe portion of one wiper blade 1004 against the nozzle-formed face of the print head over a predetermined contact width and sliding it in the direction of arrow at a predetermined speed of, for example, 150 mm/s. In this verification, the amount of ink adhering to the nozzle-formed face of the print head is set in five levels. For each level of ink adhesion to the nozzle-formed face, the contact width is changed in three levels.
The five levels set for the amount of adhering ink are: an initial ink adhesion state E in which ink adheres uniformly to the entire area of the nozzle-formed face of the print head with no apparent effect of the liquid repelling ability of the nozzle-formed face; an initial ink adhesion state D in which a significant number of large and small grains of ink adhere to the nozzle-formed face, like a state found when a relatively high density (50% or higher) recording has been performed; an initial ink adhesion state C in which ink grains are uniformly scattered on the nozzle-formed face, like a state found when a relatively intermediate density (10-50%) recording has been performed; an initial ink adhesion state B in which ink grains are sparsely present on the nozzle-formed face, like a state found when a relatively low density (less than 10%) recording has been carried out; and a state A in which no ink is present on the nozzle-formed face, like a state immediately after the print head has been replaced.
The result of this, verification is tabulated in FIG. 27. In FIG. 27, a solid black circular mark xe2x80x9cxe2x97xafxe2x80x9d indicates that the surface wiped by the wiper blade 1004 is in good condition; a white circular mark xe2x80x9c◯xe2x80x9d indicates that a small amount of ink remains on the surface at positions spaced from the nozzles, with no adverse effect on the ink ejection performance; a triangular mark xe2x80x9cxcex94xe2x80x9d indicates that a small amount of ink remains near the nozzles leaving the possibility of affecting the ink ejection performance; a cross mark xe2x80x9cxxe2x80x9d indicates that a large amount of ink remains near the nozzles, giving rise to the possibility of an ink ejection failure; and a bar mark xe2x80x9c-xe2x80x9d indicates that there is no remaining ink.
As is evident from the table of FIG. 27, keeping the contact width (overlapping length) at the second level or an intermediate length of 0.8-1.2 mm produces good wiping results for the initial ink adhesion levels B, C, D. As to the initial ink adhesion level E in which the ink cannot be repelled at all by the liquid repelling ability of the nozzle-formed face and remains over the entire area of the nozzle-formed face, however, there is a limit to what the single wiper blade can do in wiping off the adhering ink.
Further, as shown in FIG. 22A, when the nozzle-formed face 1008s of the print head 1008 has been wiped a plurality of times by the wiper blade 1010 supported on a support mount 1012, the wiping action is likely to be started with contaminating ink droplets 1006 adhering to the wipe portion of the wiper blade 1010.
In that case, when the wiping is performed by the wiper blade 1010 with the contact width set to a relatively large amount, the dirty ink droplets 1006 are rubbed against the nozzle-formed face 1008s by the wiper blade 1010, as shown in FIG. 22B. After the wiping operation, the dirty ink droplets 1006 adhere to the entire area of the wipe portion of the wiper blade 1010, as shown in FIG. 22C.
Hence, the nozzle-formed face 1008s is likely to be smeared with the dirty ink droplets 1006.
FIG. 23 shows the wipe portion (engagement surface) of the wiper blade 1016 wiping the nozzle-formed face 1014s of the print head 1014 having rows of nozzles 1018X, 1018Y and 1018Z in such a manner that the wipe portion has a predetermined contact width. The nozzle rows 1018X, 1018Y and 1018Z are arranged parallel to each other at predetermined intervals in the scan direction of the print head 1014, i.e., in the direction of arrow in FIG. 23. The print head 1014 is moved toward the scan direction indicated by the arrow of FIG. 23 relative to the wipe portion of the fixed wiper blade 1016. In FIGS. 24 and 25 described later, ink already adhering to the nozzle-formed face 1014s is not shown.
When the wipe portion (engagement surface) of the wiper blade 1016, after passing the nozzle row 1018Z in the nozzle-formed face 1014s while wiping off the adhering ink as shown in FIG. 24A, reaches the nozzle row 1018Y as shown in FIGS. 24B and 25A, a part (meniscus ME) of the ink 1020 in the nozzle row 1018Y is drawn out in the direction of arrow as shown in FIG. 25B by a capillary attraction generated in a minute clearance CL between the end face of the wiper blade 1016 and the nozzle row 1018Y in the nozzle-formed face 1014s. 
Then, the wipe portion (engagement surface) of the wiper blade 1016 moves past the nozzle row 1018Y in the nozzle-formed face 1014s and advances further toward the direction of arrow, wiping the adhering ink, as shown in FIGS. 24C and 25C. The ink 1020 is attracted by the capillary attraction to both of the front face, with respect to the moving direction, of the wiper blade 1016 near its end and the rear face opposite the front face and is carried by the blade in the direction of arrow.
In this case, when the contact width of the end portion of the wiper blade 1016 is set to the second level and the nozzle-formed face 1014s is given a liquid repelling treatment, the ink 1020 is carried relatively smoothly.
When the contact width of the wipe portion of the wiper blade 1016 is set to the first level, the contact force of the tip portion is relatively weak, so that ink may remain on the nozzle-formed face 1014s after the surface is wiped by the wiper blade 1016 although there is no possibility of the remaining ink adversely affecting the ink ejection performance. When the contact width of the wipe portion of the wiper blade 1016 is set to the third level, the contact state of the engagement surface of the wiper blade 1016 becomes unstable rendering the wiping action uneven (i.e., sticking and slipping occur), with the result that the ink may remain on the nozzle-formed face 1014s. 
When the relative moving speed of the wipe portion of the wiper blade 1016 is relatively slow (less than 50 mm/s), the amount of a part (meniscus ME) of the ink 1020 in the nozzle row 1018Y drawn out in the direction of arrow as shown in FIG. 25B becomes excessive, so that the ink may remain on the nozzle-formed face 1014s. Even where the relative moving speed of the wipe portion of the wiper blade 1016 is relatively high, as the wipe portion of the wiper blade 1016 moves in the direction of arrow wiping the ink 1020 as shown in FIG. 26A, the ink 1020 adhering to the front face, with respect to the moving direction, of the tip portion of the wiper blade 1016 may get through between the nozzle-formed face 1014s and the engagement surface of the blade tip to remain on the nozzle-formed face 1014s, as shown in FIG. 26B.
Because there is a limit to what a single wiper blade can accomplish in eliminating the problems, such as the ink on the wiper blade in turn smearing the nozzle-formed face and the ink slipping through to the rear face, it is proposed, as in Japanese Patent Application Laid-Open No. 5-254137 (1993), that blade members of the same shape are arranged opposed to each other at a predetermined interval.
In this arrangement, the nozzle-formed face of the print head approaches the wipe portion of one of the two blade members from one direction so that the wiped ink adheres mostly to the one blade member. This prevents the wiped ink from attaching to the other blade member.
Further, as described in Japanese Patent Application Laid-Open No. 7-205434 (1995) and in FIG. 28, it is also proposed that blade members with different length and different hardnesses are opposed to each other at a predetermined interval.
In FIG. 28 representing this proposal, two wiper blades 1024 and 1026 for wiping the nozzle-formed face 1028s of the print head 1028 are arranged parallel to each other on the same plane of a support mount 1030. The support mount 1030 is placed, for example, on the moving path of the print head 1028. The wiper blades 1024 and 1026 have different lengths.
The thin plate-like wiper blades 1024 and 1026 have the same thicknesses and are wide in a direction almost perpendicular to the direction of arrow in FIG. 28, i.e., to the scan direction of the print head 1028. The contact width over which the wipe portion of the wiper blade 1024 contacts the nozzle-formed face 1028s is set larger than the contact width over which the wiper blade 1026 contacts the nozzle-formed face 1028s. The contact width of the wiper blade 1024 is set at about 1.5 mm for example, while the contact width of the wipe portion of the wiper blade 1026 is set at about 0.7 mm. The interval between the wiper blades 1024 and 1026 is such that they do not interfere with each other.
With the tip portion of the wiper blade 1026 engaged at a predetermined angle with a relatively large contact force, the wiper blade 1026 first removes ink adhering to the nozzle-formed face 1028s. The wiper blade 1024 is engaged against the nozzle-formed face 1028s with a smaller contact force than that of the wiper blade 1026 to remove the ink that escaped being wiped off by the wiper blade 1026 and the ink that was drawn out from the nozzles.
This ensures that the ink that has slipped through to the rear side of the wiper blade 1026 and the ink drawn out from the nozzles are wiped away by the wiper blade 1024.
To obtain a clear and crisp image quality in the ink jet printing apparatus, it is advantageous if the gap between the nozzle-formed face of the print head and the surface of the recording medium is relatively small at about 1 mm, considering the precision of ink droplet landing position.
Where the recording medium used is so-called plain paper with no special surface treatment, other than coated paper and film with a special surface treatment, when the amount of ink ejected is relatively large (high duty printing), there is a possibility of rubbing between the recording surface and the nozzle-formed face due to cockling, making it necessary to set the gap between the nozzle-formed face of the print head and the surface of the recording medium relatively wide.
Also where the recording medium is relatively thick, the gap between the nozzle-formed face of the print head and the surface of the recording medium may need to be set relatively wide for proper printing.
To avoid contact between the nozzle-formed face of the print head and the surface of the recording medium, there is known an apparatus which has a distance adjust mechanism that can change the distance between the nozzle-formed face of the print head and the surface of the recording medium according to the thickness of the recording medium.
(1) In the configuration having the wiper blades 1024, 1026, when the distance adjust mechanism changes the distance between the nozzle-formed face of the print head and the surface of the recording medium by about 0.5 mm from a relatively narrow distance indicated by a two-dot chain line in FIG. 28 to a relatively wide distance indicated by a one-dot chain line, the contact width of the wiper blade 1026 decreases to as small as about 0.7 mm or less, which means that a sufficient contact width may not be secured.
When the distance between the nozzle-formed face of the print head and the surface of the recording medium is set relatively narrow as indicated by the two-dot chain line in FIG. 28 and the contact width over which the wiper blade 1024 contacts the nozzle-formed face 1028s is set to about 1.5 mm, the wiper blade 1024 contaminated through performing the wiping action a plurality of times may smear the nozzle-formed face 1028s. 
Considering these problems, it is a first object of the present invention to provide a cleaning method, a cleaning device of an ink jet printing apparatus using this cleaning method, and an ink jet printing apparatus having this cleaning device, in which, even when the distance between the liquid nozzle-formed face of the print head and the recording surface of the recording medium is changed, the contact widths of the cleaning members can be made appropriate values according to the distance.
(2) In the ink jet printing apparatus, there is a demand that the printing operation be able to be performed to produce a good print quality on the recording surface of the recording medium at a relatively high speed and inexpensively according to data representing characters and images.
To print characters at high speed, it is required that the number of nozzles in the print head be increased to expand the printing width per unit time and that the printing be performed at an appropriate resolution (300-600 dpi). At this time, the average print ratio per unit area in the character region (average print duty) is relatively low, for example, at about 5-10%. When an image, particularly a picture that requires smooth gradation of tone, is to be printed in good condition, the granular feel, gray scale and uniformity (no variation in density) need to be balanced. To meet this requirement, an effort has been made to reduce the amount of ink injected and the average print duty is set at about 10-40%.
Thus, the print head must be optimized according to the images or characters to be formed. The measures proposed to meet this requirement include a system that mounts both a character-dedicated print head and an image-dedicated print head, and a system that allows the use of either the character-dedicated print head or the image-dedicated print head through replacement.
During printing, the condition in which the ink adheres to the nozzle-formed face of the print head (wettability) varies according to, for example, the average print duty value mentioned above and the distance between the nozzle-formed face of the print head and the surface of the recording medium, as shown in FIGS. 29 and 30.
FIG. 29B shows the nozzle-formed face RHES of the print head RHE opposed to the recording surface of the recording medium Pa at a relatively wide distance La. In this arrangement, ink droplets IDa are shown to be ejected from a plurality of nozzles nO onto the recording surface of the recording medium Pa in such a way that the average print duty value is relatively small.
The plurality of nozzles nO, as shown in FIG. 29A, are arranged in the nozzle-formed face RHES in a direction almost perpendicular to the direction S of movement of the print head RHE.
In this case, as shown in FIGS. 29A and 29B, after an ink droplet IDa has landed the recording surface, a part of the droplet is scattered, directly adhering to the nozzle-formed face RHES or forming ink mist which in turn sticks to the nozzle-formed face RHES. These adhering ink particles are shown at IDaxe2x80x2. The sizes of these ink particles IDaxe2x80x2 are relatively small and the amount of adhering ink IDaxe2x80x2 is also relatively small.
FIG. 30B, on the other hand, shows the nozzle-formed face RHESxe2x80x2 of the print head RHExe2x80x2 opposed to the recording surface of the recording medium Pa at a relatively narrow distance Lb, which is shorter than the distance La. In this arrangement, ink droplets IDb are shown to be ejected from a plurality of nozzles nO onto the recording surface of the recording medium Pa in such a manner that the average print duty value is relatively large. In FIGS. 30A and 30B the constitutional elements identical with those of FIGS. 29A and 29B are assigned like reference numbers and their explanations are omitted.
In this case, as shown in FIGS. 30A and 30B, after the ink droplet IDb has landed the recording surface, a part of the droplet is scattered, directly adhering to the nozzle-formed face RHESxe2x80x2 or forming ink mist which in turn sticks to the nozzle-formed face RHESxe2x80x2. These adhering ink particles are shown at IDbxe2x80x2. The sizes of these ink particles IDbxe2x80x2 are relatively large and the amount of adhering ink IDbxe2x80x2 is also relatively large.
Therefore, when the print head RHE used is a monochromatic head and the print head RHExe2x80x2 is a color head, the optimum wiping should be performed for each print head. However, there are no printing apparatus that perform wiping in a manner that considers the wiping conditions of the print heads with different average print duty values.
Considering these problems, it is a second object of the present invention to provide a cleaning method, a cleaning device of an ink jet printing apparatus using this cleaning method, and an ink jet printing apparatus having this cleaning device, which can clean the liquid nozzle-formed face of the print unit under the wiping conditions suited for the print heads with different average print duty values.
(3) The ink jet printing apparatus conventionally uses similar dye-based inks of, for example, black, cyan, magenta and yellow colors in forming a color image on the recording surface of the recording medium. These inks may be changed in their composition in order to compensate for variations in the durability of the print head due to the charring of the print head heaters resulting from the difference in the kind of dye.
Further, recent years have seen an increasing tendency that a pigment-based inks rather than dye-based inks are used as black ink because characters formed on the recording surface are required to have water resistance. The pigment-based inks may lead to an ink ejection failure particularly when it adheres to the nozzle-formed face of the print head, and therefore it is necessary to remove the adhering ink thoroughly.
The pigment-based inks, however, are generally not easily dissolved again, compared with the dye-based inks, and because the properties of these inks such as viscosity and surface tension are different from those of the dye-based ink, it is difficult to reliably wipe off both the pigment-based ink and dye-based ink adhering to the nozzle-formed face of the print head at one time.
Considering these problems, it is a third object of the present invention to provide a cleaning method, a cleaning device of an ink jet printing apparatus using this cleaning method, and an ink jet printing apparatus having this cleaning device, which can reliably clean the liquid nozzle-formed face of the print unit, designed to perform printing on the recording surface of the recording medium, under the wiping condition suited for the dye ink and the pigment ink used for printing.
Further, to solve these conventional problems, it is a fourth object of the present invention to provide an ink jet printing apparatus in which the distance from the print head to the recording medium can be selectively changed and the print head is wiped by a plurality of cleaning members that correspond to the position of the print head and have different free end positions, thereby assuring good wiping and good print quality at all times without loading the print head and carriage regardless of the selected position of the print head.
(1) To achieve the first object described above, the cleaning method according to this invention comprises the steps of: when a distance between a liquid nozzle-formed face of a print unit, which performs printing on a recording surface of a recording medium, and the recording surface is adjusted to a first distance, wiping off a substance adhering to the liquid nozzle-formed face by a first cleaning member and then by a second cleaning member, the first cleaning member being arranged movable relative to the liquid nozzle-formed face of the print unit, the second cleaning member being adapted to wipe off the substance adhering to the liquid nozzle-formed face following the first cleaning member, the first and second cleaning members having different contact widths; and when the distance between the liquid nozzle-formed face of the print unit and the recording surface is adjusted to a second distance, larger than the first distance, setting the contact width of a wipe portion of the first cleaning member virtually equal to the contact width of a wipe portion of the second cleaning member associated with the first distance and wiping off the adhering substance.
The cleaning device of the ink jet printing apparatus according to the invention comprises: a cleaning member unit, the cleaning member unit further comprising: a distance adjust mechanism for adjusting in two steps a distance between a liquid nozzle-formed face of a print unit, which performs printing on a recording surface of a recording medium, and the recording surface; a first cleaning member arranged movable relative to the liquid nozzle-formed face of the print unit and adapted to wipe off with a predetermined contact width a substance adhering to the liquid nozzle-formed face; and a second cleaning member for wiping off with a predetermined contact width the substance adhering to the liquid nozzle-formed face following the first cleaning member; wherein the contact width of the wipe portion of the second cleaning member obtained when the distance between the liquid nozzle-formed face of the print unit and the recording surface is adjusted to a first distance by the distance adjust mechanism is set almost equal to the contact width of the wipe portion of the first cleaning member obtained when the distance is adjusted to a second distance, larger than the first distance.
(2) To achieve the second object, the cleaning method according to the invention is characterized in that, in the above cleaning method, the contact widths of the wipe portions of the first cleaning member and the second cleaning member are individually set based on the amount of substance adhering to the liquid nozzle-formed face of the print unit and on the distance between the liquid nozzle-formed face of the print unit and the recording surface in such a manner that a wiping state of at least one of the wipe portions of the first cleaning member and the second cleaning member differs from a wiping state of the other.
The cleaning device of the ink jet printing apparatus according to the invention is characterized in that, in the cleaning device described above, the contact widths of the wipe portions of the first cleaning member and the second cleaning member are individually set based on the amount of substance adhering to the liquid nozzle-formed face of the print unit and on the distance between the liquid nozzle-formed face of the print unit and the recording surface in such a manner that a wiping state of at least one of the wipe portions of the first cleaning member and the second cleaning member differs from a wiping state of the other.
(3) To achieve the third object, the cleaning method according to the invention is characterized in that, in the cleaning method described above, the contact widths of the wipe portions of the first cleaning member and the second cleaning member are individually set based on a dye ink or a pigment ink adhering to the liquid nozzle-formed face of the print unit and on the distance between the liquid nozzle-formed face of the print unit and the recording surface in such a manner that a wiping state of at least one of the wipe portions of the first cleaning member and the second cleaning member differs from a wiping state of the other.
The cleaning device of the ink jet printing apparatus according to the invention is characterized in that, in the cleaning device described above, the contact widths of the wipe portions of the first cleaning member and the second cleaning member are individually set based on a dye ink or a pigment ink adhering to the liquid nozzle-formed face of the print unit and on the distance between the liquid nozzle-formed face of the print unit and the recording surface in such a manner that a wiping state of at least one of the wipe portions of the first cleaning member and the second cleaning member differs from a wiping state of the other.
(4) To achieve the fourth object, the ink jet printing apparatus according to the invention is characterized in that the distance from the print head to the recording medium can be selectively changed and the print head is wiped by a plurality of wiper blades as cleaning members that correspond to the position of the print head and have different free end positions, thereby assuring good wiping and good print quality at all times without loading the print head and carriage regardless of the selected position of the print head.
Further, the ink jet printing apparatus according to the invention is characterized by a print means for ejecting ink from nozzles onto a recording medium for printing; an ejection recovery means for recovering the ejection performance by engaging the print means; a selector mechanism for selecting a distance between the print head and the recording medium; and a cleaning means having a plurality of cleaning members, the cleaning members having different free end positions according to the distance between the print head and the recording medium.
The ink jet printing apparatus according to the invention is characterized in that the free ends of the plurality of the cleaning members are positioned so that the forces of the cleaning members when they engage the print head are virtually equal among the cleaning members.
The ink jet printing apparatus according to the invention is characterized in that the free ends of the plurality of the cleaning members are positioned so that the deflections of the cleaning members when they engage the print head are virtually equal among the cleaning members.
Further, the ink jet printing apparatus according to the invention is characterized in that the free ends of the plurality of the cleaning members are positioned so that the engagement angles of the cleaning members when they engage the print head are virtually equal among the cleaning members.
Further, the ink jet printing apparatus according to the invention is characterized by a selector mechanism for selecting the distance between the print head and the recording medium and by the plurality of the cleaning members with different lengths according to the distance between the print head and the recording medium.
The ink jet printing apparatus according to the invention is characterized by a selector mechanism for selecting the distance between the print head and the recording medium and by the plurality of the cleaning members with different lengths and different thicknesses according to the distance between the print head and the recording medium.
Further, the ink jet printing apparatus according to the invention is characterized in that an absorbent body is disposed between the cleaning members.
Further, the ink jet printing apparatus according to the invention is characterized in that the cleaning members are arranged in the direction of movement of the print head and the cleaning member to be used is selected by the carriage position according to the distance between the print head and the recording medium.
Further, the ink jet printing apparatus according to the invention is characterized in that the distance that the print head is moved by the print head position selector mechanism and the height difference between the cleaning members are set almost equal.
The ink jet printing apparatus according to the invention is characterized in that it includes: a selector mechanism for switching the position of the print head relative to the recording medium between a first print head position and a second print head position; and first and second cleaning members corresponding to the first print head position and the second print head position; wherein an engagement condition in which the first cleaning member engages the print head at the first print head position is almost identical with an engagement condition in which the second cleaning member engages the print head at the second print head position.
Further, the ink jet printing apparatus according to the invention is characterized in that the print head has an electrothermal transducer that generates thermal energy for ejecting ink.
In the ink jet printing apparatus of this invention, which comprises a print means for ejecting ink from nozzles onto a recording medium for printing, an ejection recovery means for recovering the ejection performance by engaging the print means, a selector mechanism for selecting a distance between the print head and the recording medium, and a cleaning means having a plurality of cleaning members, the cleaning members having different free end positions, lengths and/or thicknesses according to the distance between the print head and the recording medium; the cleaning method and the cleaning device of the ink jet printing apparatus using this cleaning method according to this invention are characterized in that the free ends of the plurality of cleaning members are positioned so that the forces, deflections and engagement angles of the cleaning members when they engage the print head are virtually equal among the cleaning members, that an absorbent body is arranged between the cleaning members, that the cleaning members are arranged in the direction of movement of the print head and the cleaning member to be used is selected by the carriage position according to the distance between the print head and the recording medium, and that the distance that the print head is moved by the print head position selector mechanism and the height difference between the cleaning members are set almost equal. Because of this arrangement, the print head can be wiped in good condition at all times without loading the print head and the carriage regardless of the selected print head position.
The above and other objects, effects, features and advantages of the present invention will become apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.